Outcomes in ambulatory chronic systolic and diastolic heart failure: A propensity score analysis

Abstract

Prior studies demonstrating significant difference in outcomes in systolic and diastolic heart failure (HF) are often limited to hospitalized acute HF patients, and may be confounded by residual bias. In this analysis, we examined long-term mortality and hospitalization in a propensity score matched cohort of ambulatory chronic systolic and diastolic HF patients. Of the 7788 patients in the Digitalis Investigation Group trial, 6800 had systolic HF (ejection fraction >45%) and 988 had diastolic HF (ejection fraction >45%). We restricted our analysis to 7617 patients without valvular heart disease: 916 diastolic HF and 6701 systolic HF. Propensity scores for diastolic HF, calculated for each patient by a non-parsimonious multivariable logistic regression model, were used to match 697 diastolic HF with 2091 systolic HF patients. Matched Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for outcomes in diastolic (versus systolic) HF. During a median 38-month follow-up, compared with 32% mortality in systolic HF, 23% of diastolic HF patients died (HR=0.70; 95% CI=0.59-0.84; P<.0001). Respective HR (95%CI) for cardiovascular and HF mortality were 0.60 (0.48-0.74; P<.0001) and 0.56 (0.39-0.79; P=.001). All-cause hospitalizations occurred in 64% of systolic and 67% of diastolic HF patients (HR=0.99; 95% CI=0.87-1.11; P=0.801). Respective HR (95%CI) for cardiovascular and HF hospitalizations were 0.84 (0.73-0.96; P=.011) and 0.63 (0.51-0.77; P<.0001). Despite lower mortality and cardiovascular morbidity, diastolic HF patients had similar overall hospitalizations as in systolic HF. Ejection fraction should be assessed in all HF patients to guide therapy, with special attention to non-cardiovascular morbidity in diastolic HF.